1. Field
Example embodiments relate to a dendrimer, an organic memory device having the dendrimer, and a method of manufacturing the organic memory device.
2. Description of the Related Art
The demand for memory devices has increased with the growth of information and communication industries. For example, the use of portable computers or electronic apparatuses (e.g., portable terminals, smart cards, electronic cash, personal digital assistants, digital audio players, and multimedia players) has increased. The memory devices for these apparatuses may be nonvolatile memory devices, wherein recorded information is not erased when power sources are turned off.
As LSI (Large Scale Integration) technologies advance, the number of bits of memory integrated in an IC chip may attain megabit levels. Thus, submicron circuit line width may be required. Conventional nonvolatile memory devices may be memory devices based on a standard silicon process. However, these conventional memory devices may have a more complex structure and larger-sized memory cells. Consequently, realizing higher capacity memory devices may be more difficult. Furthermore, a fining process, wherein line width per unit area is decreased, may be required to obtain higher integrated memory capacities for memories based on silicon. As a result, the manufacturing cost of memory chips may increase, and further miniaturization of the memory chips may be restricted by technical limitations, thus decreasing profitability.
Accordingly, next-generation memories having higher speeds, higher capacities, and lower power consumption are being developed as suitable alternatives to conventional memories for developing wireless portable information and communication systems and apparatuses for processing relatively large amounts of information. Types of next-generation memories may include ferroelectric RAM, ferromagnetic RAM, phase change RAM, nanotube RAM, holographic memory, and organic memory, depending on the material constituting a cell, which is a basic unit in a semiconductor. Among the next-generation memories, organic memories may realize memory properties by using the bistability of voltage values obtained by introducing an organic material between the upper and lower electrodes and applying a voltage thereto. Thus, organic memories may overcome limits of processibility, manufacturing costs, and degrees of integration (disadvantages of conventional flash memory) while realizing nonvolatility (advantage of conventional flash memory).
A conventional semiconductor device may include an intermediate layer provided between the upper and lower electrodes, wherein the intermediate layer may be formed by mixing an ionic salt (e.g., NaCl or CsCl) with a conductive polymer. The semiconductor device may realize switching and memory characteristics by exploiting a charge separation phenomenon caused by an electric field. However, when the semiconductor device is manufactured using the conductive polymer, realizing accurate molecular weight and distribution may be more difficult even if spin coating may be performed. Thus, reproduction of the intermediate layer may not be easy, thereby resulting in less uniform device characteristics.
A conventional memory device may use ferroelectricity based on the crystalline state of fluorine polymers (e.g., poly(vinyldifluoroethylene)). However, when a memory device is manufactured using fluorine polymer, a coating process may be more difficult to perform because of the hydrophobicity of fluorine, thereby decreasing processibility. Furthermore, information may be recorded only once and must be read optically, thereby increasing the size and complexity of the device.